1. Field of the Invention
The invention relates to marine vessel bridge systems, particularly with respect to interfacing sensors thereto.
2. Description of the Prior Art
Integrated bridge systems for marine vessels are prevalent in the art which interface a plurality of sensors to a main system. For example, such systems are known that transfer data between a Main Radar System and sensors. Such sensors include gyrocompasses, speed logs, RS 232 sensor networks, analog and alarm hardware, radar transceiver and inter switch controls. The main system inputs and computes data pursuant to system operation. The compass interface in such present day bridge systems requires the operator to synchronize system heading with the gyrocompass or heading repeaters every time the system is turned on. Generally such systems do not provide for continuous compass interface during power-down. The synchronization process is time consuming, and may also be hazardous after a transient power failure with respect to collision avoidance radar.
Sensor interface software in most shipboard systems is designed to initialize all subsystems after hardware power-up, enable internal and sensor interrupts, provide a task executive to schedule and time-share periodic processing tasks, and provide interrupt handlers to perform minimal data collection and control. Major data processing is accomplished by the periodic tasks or background tasks, in which data protection schemes are required to prevent intervening computer interrupts from destroying data being processed. This multi-layered software system is complex, resulting in high design and maintenance costs. In order to provide continuous compass interface with such interrupt handler/task partitioned systems, it is required that the memory and timer components which run the executive and tasks must always be powered. Such systems cannot be easily downgraded to service a subset of sensors after main power has been removed.